What Ubuntu installation means and why you'd do it

Installing Ubuntu means replacing your current operating system — Windows or macOS — with Ubuntu, a free Linux-based system. You're not adding Ubuntu alongside what you have; you're writing over your hard drive with a new operating system that boots when you turn on your computer.

Most people install Ubuntu because they want a system they control more directly, one that doesn't phone home to a corporation, or one that runs on older hardware that Windows no longer supports. Some install it to learn how operating systems actually work. Others do it because Ubuntu is free and they don't want to pay for Windows licenses.

Installation is not reversible without a backup of your old system. Once you start, your old operating system is gone unless you saved it first. This guide walks you through the process, but you need to understand that step: you will lose everything on that drive.

Key Takeaways

  • You need a USB stick at least 4 gigabytes in size, a computer you're willing to erase completely, and about 30 minutes of uninterrupted time.
  • The first step is downloading Ubuntu from ubuntu.com and writing it to the USB stick using a tool like Balena Etcher or Rufus — this is not the same as copying a file.
  • You boot from the USB stick by restarting your computer and pressing a specific key during startup (usually F12, Esc, or Del, depending on your computer's maker).
  • The Ubuntu installer will ask you to erase your drive and choose a language and keyboard layout — these choices are permanent once you confirm.
  • After installation finishes and you restart, your computer will boot into Ubuntu, and you'll set up a user account and password before you can use it.

Gathering what you need before you start

You need three things: a USB stick, a computer to install on, and a second computer or device to read Ubuntu and create the bootable USB. The USB stick must be at least 4 gigabytes — most modern USB sticks are 16 or 32 gigabytes, which is more than enough. Anything smaller than 4 gigabytes will not work.

The computer you're installing on will have its entire hard drive erased. Everything on it — documents, photos, programs, your operating system — will be gone. Before you plug in that USB stick, back up anything you want to keep. Copy it to an external drive, upload it to cloud storage, or move it to another computer. Do this now, not after you've started the installation.

You also need to know your computer's make and model, or at least the brand. This matters because different manufacturers use different keys to enter the boot menu during startup. Dell, HP, Lenovo, and Apple all use different keys. You'll find this information in your computer's manual or by searching online for "[your computer brand] boot menu key".

Downloading Ubuntu and creating a bootable USB stick

Go to ubuntu.com in a web browser on your second computer. Click the read button and choose the latest long-term support version — it will be labeled "LTS" and is the most stable choice for most people. This downloads an ISO file, which is a complete copy of Ubuntu compressed into one file. The file is about 3 gigabytes, so it may take several minutes depending on your internet speed.

Once the read finishes, you need to write this file to your USB stick using a tool that understands ISO files. Do not drag and drop the file onto the USB stick — that will not work. Instead, read Balena Etcher (balena.io/etcher) if you're on Windows or macOS, or Rufus (rufus.ie) if you're on Windows. These programs take the ISO file and write it to the USB stick in a way that makes the stick bootable — meaning your computer can start up from it.

Open Balena Etcher or Rufus. Select the ISO file you downloaded, select your USB stick from the list of drives, and click the button to write. The program will warn you that everything on the USB stick will be erased — that's normal and expected. Wait for the write to finish. This usually takes 5 to 15 minutes. When it's done, safely eject the USB stick.

Restarting your computer and entering the boot menu

Plug the USB stick into the computer you want to install Ubuntu on. Restart that computer completely — don't just put it to sleep. As soon as you press the power button or restart, start pressing the boot menu key repeatedly. The key depends on your computer's brand: Dell uses F12, HP uses Esc, Lenovo uses F12 or Enter, and Apple uses Option. If you're not sure, search online for "[your computer brand] boot menu key" before you restart.

Press the key every second or so as the computer starts up. You're aiming for a menu that shows a list of devices your computer can boot from — USB drives, hard drives, CD drives, and so on. If you see a Windows or macOS login screen, you waited too long and the computer booted normally. Restart again and press the key faster.

When the boot menu appears, look for an entry that mentions your USB stick. It might say "USB Drive", "UEFI: [USB stick name]", or just show the manufacturer of your USB stick. Select it and press Enter. The computer will now boot from the USB stick instead of your hard drive.

Walking through the Ubuntu installer

After a few seconds, you'll see the Ubuntu installer welcome screen. It will ask you to choose a language — select the language you want Ubuntu to use. Then it will ask whether you want to try Ubuntu first or install it. Choose "Install Ubuntu" to proceed. Do not choose "Try Ubuntu" unless you want to explore first; trying Ubuntu does not install anything, and you'll have to start over.

The installer will ask about keyboard layout. If you use a standard US keyboard, the default is correct. If you use a different layout — UK, French, German, or another language — select it now. This choice affects how your keyboard works after installation, so get it right.

Next, the installer asks about internet connection and updates. You can skip this or connect to your Wi-Fi network. Connecting allows Ubuntu to read updates during installation, which saves time later. If you're not connected to the internet, that's fine — you can update after installation finishes.

Choosing how to erase your drive and confirming the installation

The installer will now show you the hard drives it found in your computer. This is the critical moment. It will ask how you want to install Ubuntu and will show options like "Erase disk and install Ubuntu" or "Something else". Choose "Erase disk and install Ubuntu" unless you have a specific reason to partition your drive differently — most people don't.

The installer will show you which drive it plans to erase. Make absolutely sure this is the drive you want to erase. If you have multiple drives, the installer might pick the wrong one. Check the size and name. If it's showing the wrong drive, go back and select the correct one. Once you confirm, there is no undo.

Click the button to confirm and begin installation. The installer will erase your drive and write Ubuntu to it. This takes 10 to 20 minutes depending on your computer's speed. You'll see a progress bar. Do not unplug the USB stick, restart the computer, or close the installer during this time.

Completing setup after installation finishes

When the installer finishes, it will ask you to restart your computer. Click the button to restart. The installer will tell you to remove the USB stick — do this before the computer restarts, or it will boot from the USB stick again instead of from your new Ubuntu installation.

After you remove the USB stick and the computer restarts, Ubuntu will boot for the first time. You'll see a setup screen asking you to create a user account. Enter a name for your account, a username (usually lowercase, no spaces), and a password. Write down your password somewhere safe — you'll need it to install programs and change system settings later.

Once you've created your account, Ubuntu will finish setting up and show you the desktop. You now have a working Ubuntu system. Your old operating system is completely gone, and Ubuntu is now the system that runs when you turn on your computer.

What to do if something goes wrong during installation

If your computer doesn't boot from the USB stick, you pressed the boot menu key too late or too early, or you selected the wrong device from the menu. Restart and try again, pressing the key more consistently. If the boot menu doesn't appear at all, your computer might have a feature called find Boot that prevents booting from USB. Restart, enter your computer's BIOS or UEFI settings (usually by pressing F2, F10, or Del during startup), and look for an option to disable find Boot.

If the installer crashes or freezes during the installation process, restart your computer, plug in the USB stick again, and start over. The installer is designed to handle this — you won't damage anything by restarting.

If Ubuntu installs but won't start up after you restart, the installer may not have written the bootloader correctly. This is rare, but if it happens, plug in the USB stick again, boot from it, and look for a "Repair" or "Troubleshoot" option in the installer menu. If you can't find one, you may need to reinstall.

Frequently Asked Questions

Can I install Ubuntu without erasing Windows?

Yes, but it requires partitioning your drive, which is more complex. During installation, choose "Something else" instead of "Erase disk and install Ubuntu", then manually create a partition for Ubuntu on your existing drive. This keeps Windows and Ubuntu on the same computer, and you choose which one to boot when you start up. This approach is riskier for beginners because a mistake can erase both systems.

What if I change my mind after installing Ubuntu?

You can reinstall Windows or macOS, but you'll need installation media or a product key. If you kept a backup of your old system before installing Ubuntu, you can restore it. Otherwise, you'll need to purchase Windows or have access to macOS installation files. This is why backing up before installation is critical.

Will Ubuntu run on my old computer?

Ubuntu runs on most computers made in the last 15 years, even older ones that Windows 11 won't support. If your computer has at least 2 gigabytes of memory and 20 gigabytes of disk space, Ubuntu will likely work. Very old computers might run slowly, but they'll run. Test by booting from the USB stick without installing — you can try Ubuntu first to see how it performs.

Do I need to know Linux to install Ubuntu?

No. The installer is designed for people who have never used Linux. You make a few choices about language and keyboard, confirm that you want to erase the drive, and the installer handles the rest. After installation, you can learn Linux gradually as you use the system, or stick to the graphical interface if you prefer.

How long does the whole process take?

From downloading Ubuntu to having a working system usually takes 45 minutes to an hour for a first-time installer. Downloading Ubuntu takes 10 to 20 minutes depending on your internet speed. Writing to the USB stick takes 5 to 15 minutes. Installation itself takes 10 to 20 minutes. Setup after installation takes 5 minutes. The actual hands-on time is much less — most of it is waiting for downloads and installation to finish.